Docker and Portainer

Posted under » Ubuntu » Linux on 27 Apr 2024

Right now I don't have time to explain why we should be using docker but it is hard to ignore it. Install according to your specs and it has changed a lot in just months.

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc
# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

Now we install docker proper

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

At this stage you don't need sudo.

Docker containers are built from Docker images. By default, Docker pulls these images from Docker Hub. Let's test if we can pull an image.

$ service docker start
$ docker run hello-world

In some cases you have to pull the images

docker pull httpd

To look at your local images

$ docker images

To see running dockers

$ docker ps
$ docker ps -a

To start a stopped container, use docker start, followed by the container ID. To stop a running container, use docker stop, followed by the container ID or namei. Once you’ve decided you no longer need a container anymore, remove it with the docker rm.

$ docker start 1c08a7a0d0e4
$ docker stop ubuntu
$ docker rm ubuntu

Maybe this is all too hard to remember so I recommend that you docker this app called Portainer

Portainer needs persisting data (for storing user password for example). Let's create a docker volume to store this data.

$ docker volume create portainer_data
$ docker volume inspect portainer_data 

Now run it on port 9000

$ docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:2.21.4

Here is the detail of each option:

• docker run is the base command to start a container
• -d means detach. It runs the container in background.
• -p expose UI over the port 9443, portainer GUI will be at URL hostname:9443
• the ip must be valid. Here is mine https://192.168.18.56:9443/ sometimes our port 80 is using another IP from the router.
• --name=portainer names the container portainer
• --restart=always always restart Portainer (after a crash or at machine or deamon restart)
• -v /var/run/docker.sock:/var/run/docker.sock mounts the volume /var/run/docker.sock from the host machine to the Portainer container.
  /var/run/docker.sock is actually the Docker daemon socket. Portainer needs this socket to get Docker status.
• -v portainer_data:/data mounts the volume created previously portainer/portainer-ce is the name of the Portainer Community Edition image.

The first time Portainer starts, it asks you to set a password. The password must be at least 12 characters. Once the password is entered, you are in business.